Nassau County’s 19 Legislative districts will be changing later this year, but no one knows yet how dramatic those adjustments are going to be.

The Temporary District Advisory Commission, which was charged by county government with drafting a redistricting proposal, turned out two plans to revise the legislative districts, one from the commission’s Republicans and the other from its Democrats. The proposals were presented at a public hearing at the county legislative chambers on Jan. 3.

The Republican plan would dramatically change boundaries and move more than 600,000 residents into different districts. The Democratic plan largely keeps current districts intact while making some adjustments to the lines to account for population shifts. It would move about 25,000 people into new districts.

“There have been dramatic changes in this county in the past 20 years, but there have not been dramatic changes in the maps,” said Frank Moroney, the Republican chairman of the commission.

In creating the Republican map, Moroney said, consultants were told to take a fresh look at the county using current demographics, create a plan that met state and federal constitutional standards and consider testimony from a series of public hearings in the fall. Additionally, he said, incumbency was not to be a factor. Four of the districts created have no sitting legislator.

The plan would put seven incumbents in three districts. Legislative Minority Leader Kevan Abrahams (1st District) and Legislators Joseph Scannell (5th District) and David Denenberg (19th District), all Democrats, would live in the same district. The same would be true on the north shore, where Democratic legislators Judy Jacobs and Delia DeRiggi-Whitton would live in the same district, as would Republicans Joseph Belisi and Michael Venditto in southeastern Nassau.

Moroney added that the Republican plan would create three minority districts with demographics similar to those in the Democratic plan.